 (defn migrate-2016-03-21
   "Add user preferences"
   []
-  (d/transact db/*conn*
+  (d/transact db/conn
     [{:db/ident :user/preferences
       :db/valueType :db.type/string
       :db/cardinality :db.cardinality/one

  group and add all existing users and tags to that group"
  [group-name]
  (let [group (db/create-group! {:id (db/uuid) :name group-name})
        all-users (->> (d/q '[:find ?u :where [?u :user/id]] (d/db db/*conn*)) (map first))
        all-tags (->> (d/q '[:find ?t :where [?t :tag/id]] (d/db db/*conn*)) (map first))]
    (d/transact db/*conn* (mapv (fn [u] [:db/add [:group/id (group :id)] :group/user u]) all-users))
    (d/transact db/*conn* (mapv (fn [t] [:db/add t :tag/group [:group/id (group :id)]]) all-tags))))

(defn migrate-2015-08-26
  "schema change for invites"
  []
  (d/transact db/*conn*
    [
     ; invitations
     {:db/ident :invite/id

(defn migrate-2016-03-04
  "Add extension type as attribute"
  []
  (d/transact db/conn
    [{:db/ident :extension/type
      :db/valueType :db.type/keyword
      :db/cardinality :db.cardinality/one
